Rainbow Electronics LM63 - Manual (Page 21)

2.0 LM63 Registers
(Continued)
Remote Diode Temperature, Offset And Setpoint Registers
ADDRESS
Hex
Read/
Write
Bits
POR
Value
Name Description
01
Read
Only
7:0 N/A
Remote Diode
Temperature
Reading (MSB)
This is the MSB of the 2’s complement value, representing the
temperature of the remote diode connected to the LM63. Bit 7 is the sign
bit, bit 6 has a weight of 0x40 (64˚), and bit 0 has a weight of 1˚C. This
byte to be read first.
10
Read
Only
7:5 N/A
Remote Diode
Temperature
Reading (MSB)
This is the LSB of the 2’s complement value, representing the
temperature of the remote diode connected to the LM63. Bit 7 has a
weight 0.5˚C, bit 6 has a weight of 0.25˚C, and bit 5 has a weight of
0.125˚C.
4:0 00 Always 00.
11 R/W 7:5 00
Remote
Temperature
OFFSET (MSB)
These registers contain the value added to or subtracted from the
remote diode’s reading to compensate for the different non-ideality
factors of different processors, diodes, etc. The 2’s complement value, in
these registers is added to the output of the LM63’s ADC to form the
temperature reading contained in registers 01 and 10.
12 R/W
7:5 00
Remote
Temperature
OFFSET (LSB) 4:0 00 Always 00.
07 (0D) R/W 7:0
0x46
(70˚C)
Remote HIGH
Setpoint (MSB)
High setpoint temperature for remote diode. Same format as Remote
Temperature Reading (registers 01 and 10).
13 R/W
7:5 00 Remote HIGH
Setpoint (LSB) 4:0 00 Always 00.
08 (0E) R/W 7:0
00
(0˚C)
Remote LOW
Setpoint (MSB)
Low setpoint temperature for remote diode. Same format as Remote
Temperature Reading (registers 01 and 10).
14 R/W
7:5 00 Remote LOW
Setpoint (LSB) 4:0 00 Always 00.
19 R/W 7:0
0x55
(85˚C)
Remote Diode
T_CRIT Limit
This 8-bit integer storing the T_CRIT limit is nominally 85˚C. This value
can be changed once after power-up by setting T_CRIT Limit Override
(bit 1) in the Configuration register to a 1, then programming a new
T_CRIT value into this register. The T_CRIT Limit can not be changed
again except by cycling power to the LM63.
21 R/W 7:0
0x0A
(10˚C)
Remote Diode
T_CRIT
Hysteresis
8-bit integer storing T_CRIT hysteresis. T_CRIT stays activated until the
remote diode temperature goes below [(T_CRIT Limit) — (T_CRIT
Hysteresis)].
BF R/W
7:3 00000 These bits are unused and should always set to 0.
2:1 00
Remote Diode
Temperature
Filter
00: Filter Disabled
01: Filter Level 1 (minimal filtering, same as 10)
10: Filter Level 1 (minimal filtering, same as 01)
11: Filter Level 2 (maximum filtering)
0 0
Comparator
Mode
0: the ALERT/Tach pin functions normally.
1: the ALERTTach pin behaves as a comparator, asserting itself when
an ALERT condition exists, de-asserting itself when the ALERT condition
goes away.
LM63
www.national.com 21